underliningvsunderminingWhat's the difference?

Quick tell: underlining is a verb, undermining is a noun, so they fill different roles in a sentence.

Which to use

“underlining” is a verb and “undermining” is a noun - they look or sound alike but fill different roles in a sentence.

#42,468
“underlining” frequency rank
#19,238
“undermining” frequency rank
61706
confusion score

Side-by-Side Comparison

Feature underlining undermining
Definition present participle and gerund of underline The act or process by which something is undermined.

Letter map: underlining vs undermining

Shared letters muted; letters that set underlining and undermining apart highlighted. Shared run: 10.

11 ch
underlining
11 ch
undermining

Role in the sentence - underlining and undermining

Our dataset has no pronunciation recorded for both members, so the reliable separator here is grammatical: underlining is averb and undermininganoun. On the page they differ by a single letter - l in “underlining” becomes m in “undermining”. Our composite confusion score for this pair is 61706, derived from the frequency rank of both members and their visual similarity.

underlining is recorded at frequency rank #42,468, classified as averb. undermining is at rank #19,238, tagged as anoun.

Glosses for this pair are partially populated in our dataset, but the full side-by-side definitions above should still guide you to the right choice.

With a confusion score of 61706, this pair ranks #92,679 of 530,003 scored English confusable pairs - among the most confusable pairs.

Orthographic DNA of underlining vs undermining

Shared letters: deginru. Private to "underlining": l. Private to "undermining": m.

"underlining" · 11 letters · shape VCCVCCVCVCC  ·  "undermining" · 11 letters · shape VCCVCCVCVCC

Known mistypes of this pair

  • underliningnuderlining · udnerlining · undderlining · undelrining · underilning · underliinng · underlinign · underliningg
  • underminingnudermining · udnermining · unddermining · undemrining · underimning · undermiinng · underminign · underminingg

Frequently Asked Questions

Is swapping "underlining" for "undermining" ever safe?
No - they are not even the same part of speech. "underlining" is a verb and "undermining" a noun, so a sentence built for one is usually ungrammatical with the other.
Which is more common, "underlining" or "undermining"?
"undermining" is the more common of the two: it sits at frequency rank #19,238 in our English list, against #42,468 for "underlining". The two are close in frequency, so neither is a safe default; check the meaning rather than guessing.

After this comparison

Pair "underlining" vs "undermining" is on the table, pick a follow-up below.

  • Full dictionary entry for "underlining" with definition, IPA, and generated misspellings. Word entry
  • Full dictionary entry for "undermining" - compare definitions side by side with the headword page. Word entry
  • This pair ranks #92,679 of 530,003 scored English confusable pairs in this corpus vintage. Corpus statistics
  • "underlining" and "undermining" also get mixed up with nearby pairs, the highest-scored neighbour is "underlining vs underpinning". Nearby pair
  • Recorded mistypes exist for at least one side of this pair, useful when a spell-checker or OCR lands on the wrong form. See mistypes

Confusion rank #92,679 of 530,003 scored English pairs, corpus vintage 2026-09-03, not spelling advice.

Source: Wiktionary (via kaikki.org) Structured Wiktionary extract

Source: FrequencyWords open word-frequency list